Virginia head coach Mike London, center, reacts to a play with linebacker Henry Coley (44) and guard Conner Davis (74) during the first half of an NCAA college football game against UCLA at Scott Stadium, Saturday, Aug. 30, 2014, in Charlottesville, Va. (AP Photo/Andrew Shurtleff)
(The Associated Press)

Georgia Tech defensive back Lance Austin (17) breaks up a pass intended for Wofford running back Octavius Harden (33) during the second half of an NCAA college football game, Saturday, Aug. 30, 2014, in Atlanta. Georgia Tech won 38-19. (AP Photo/Mike Stewart)
(The Associated Press)

North Carolina State head coach Dave Doeren motions to the officials during the second half of an NCAA college football game against Georgia Southern, Saturday, Aug. 30, 2014, in Raleigh, N.C. N.C. State won 24-23. (AP Photo/The News & Observer, Ethan Hyman)
(The Associated Press)

Defenses in the Atlantic Coast Conference aren't waiting for passing situations to bring on another defensive back.

Instead, they're starting with the nickel package.

Teams are adding a fifth defensive back to chase receivers. They're creating hybrid positions for players fast enough to stay in coverage but physical enough to play the run. It's an effort to cover more ground and avoid mismatches against offenses that keep attacking from sideline to sideline without substituting.

"You're trying to match speed," Georgia Tech defensive coordinator Ted Roof said. "You can disguise numbers and get people in the box. But when you know they're going to throw it, everybody in the stands knows they're going to throw it, you want to be able to match up.

"Football is evolving. It's changed. It's always changing. You've got to be able to match up personnel."

Programs across college football have long used nickel packages. But they're becoming the norm, especially as defenses constantly shift into multiple alignments — often against no-huddle offenses — to match up on every snap.

Duke, Georgia Tech, North Carolina, North Carolina State, Virginia Tech and Wake Forest are using a 4-2-5 — four linemen, two linebackers and five defensive backs — as their base scheme and the starting point for what they do every week.

Other teams are using the nickel heavily, including reigning national champion Florida State.

The school lists the defense as a 4-3 base with multiple looks — four linemen, three linebackers — but the DB-rich Seminoles began using more nickel a few games into last season. Coach Jimbo Fisher said his team ran nickel 71 percent of the time last season, including as the starting lineup for the BCS title game against Auburn.

"It's hard to (match up) when you don't play nickel packages," Fisher said. "The reasons we're in it a lot is because teams are in three and four wides most of the time."

The Seminoles ranked as one of the nation's best defenses last year while giving up an ACC-low 4.1 yards per play. The Hokies, led by longtime coordinator Bud Foster, were second by allowing 4.5 yards, while UNC was sixth in the 14-team league at 5.3, according to STATS.

"If you had 10 of the 14 teams in the ACC that were going to line up in the I (formation) and play smashmouth with you, you wouldn't be a 4-2-5 team," said former Wake Forest coach Jim Grobe, now working as an ACC TV analyst.

"But the truth of the matter is most people are trying to spread you out and throw the football around a lot. If you're going to play teams that go up-tempo and don't substitute and make you keep your personnel group on the field, you'd say your best matchups from the start would be five defensive backs and adjust if you play a team bent on playing smashmouth football."

Former Clemson coach Tommy Bowden also pointed to another reason: supply and demand.

"Some of the dominant teams, they can go get the big guys that can run — the LSUs, the Ohio States," said Bowden, now an ACC TV analyst. "Well, the two- or three-star guys are the 6-foot-1, 195-pound guys that can run and hit. They're just not 6-2, 225 — they're going to Alabama. Some of it is who (schools) can get and those guys are more in number than the bigger guys" who run well.

The key is having defensive backs physical enough to fill running lanes while and athletic enough to cover a receiver or tackle in open space, the latter being the type of matchup that often abused slower linebackers.

Virginia coach Mike London, a former defensive coordinator who also coached in the NFL, said he sees the evolution continuing and defenses going to maybe two defensive linemen while loading up with linebackers and defensive backs in coming years.

"However you cut it, you're going to have 11 guys out there," UNC coach Larry Fedora said. " ... I don't need those four linebackers that are 255 pounds that are playing in a phone booth anymore. You just don't need them."